A creative and constructive partnership between different psychotherapies needs to develop if a psychotherapeutic psychiatry is to flourish. The greatest threat to the development of psychotherapeutic psychiatry is the partisan approach of the psychotherapies themselves. Prejudicial attitudes prevent acquisition of useful knowledge and its appropriate assimilation in psychiatric settings. The concepts of the self and borderline personality are used to show how understanding different psychotherapeutic approaches can inform treatment and further the development of a fruitful psychotherapeutic psychiatry which is itself essential for the treatment of severe personality disorder.